Remote Ischemic Preconditioning Mechanism Study

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2013 by Wake Forest Baptist Health
Sponsor:
Information provided by (Responsible Party):
Scott A Miller, Wake Forest University Baptist Medical Center
ClinicalTrials.gov Identifier:
NCT01541436
First received: February 3, 2012
Last updated: May 28, 2013
Last verified: May 2013
  Purpose

This research is being done because pain is a significant problem for patients with a variety of medical problems and following surgery or traumatic injury. Currently available pain medications may not relieve all types of pain or may relieve pain only at doses that produce side effects and potential complications.

Although Remote Ischemic Preconditioning (RIPC) appears promising, there remain several unanswered questions about how it works. This research trial will help determine how RIPC may activate the bodies natural pain control system. The goals of this study are to see if RIPC has any effect 1) on a small area of skin that will be expose to a small amount of UV- B radiation (a mild sunburn), 2) on acute thermal heat temperatures that will be applied to skin, and 3) on the sunburn-like sensation to light touch after putting capsaicin cream (the active ingredient in hot chili peppers) on skin.

Remote ischemic preconditioning is done by inflating a balloon (very similar to a blood pressure cuff) on the leg until it blocks blood flow for a few minutes. The cuff is then deflated and blood flow resumes. The process is repeated up to three times. This procedure causes the body to increase its natural pain relief system that may help to decrease the amount of postsurgical pain.


Condition Intervention
Pain
Device: Remote Ischemic Preconditioning, Capsaicin, UV-B

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Remote Ischemic Preconditioning Effects on Central and Peripheral Sensitization in Healthy Volunteers-A Pilot Study

Resource links provided by NLM:


Further study details as provided by Wake Forest Baptist Health:

Primary Outcome Measures:
  • Areas of hyperalgesia and allodynia to mechanical stimuli. [ Time Frame: 24 hours ] [ Designated as safety issue: No ]
    Hyperalgesia will be measured with vonFrey fibers and allodynia will be measured with a cotton wisp. The area will be measured in cm2.


Secondary Outcome Measures:
  • Pain intensity and unpleasantness to mechanical stimuli [ Time Frame: 24 hours ] [ Designated as safety issue: No ]
    Using a Visual Analog Sliding Scale the intensity and unpleasantness will be measured in centimeters.

  • Presence of parathesias where RIPC was used [ Time Frame: 24 hours ] [ Designated as safety issue: No ]
    After a brief tourniquet application I fully expect participants to have some degree of parasthesias. Using a standard rating scale I will record and report this.


Estimated Enrollment: 24
Study Start Date: March 2012
Estimated Study Completion Date: December 2013
Estimated Primary Completion Date: October 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Capsaicin, UV-B, RIPC Device: Remote Ischemic Preconditioning, Capsaicin, UV-B
The participants will have one disposable tourniquet applied to the left mid thigh by research personnel. The participants will then be randomized to the treatment group or sham group. The treatment group will receive 3 cycles of RIPC to the left lower leg by occluding blood flow at the thigh with a pneumatic cuff. Each cycle will consist of 5 minutes of ischemia by inflating the cuff to 300 mmHg followed by 5 minutes of reperfusion. The sham group will have the cuff inflated to no more than 15mmHg for three cycles as described above. Areas of hypersensitivity and allodynia will be obtained every 40 min for 280 min following the end of capsaicin application.
Sham Comparator: Capsaicin, UV-B Device: Remote Ischemic Preconditioning, Capsaicin, UV-B
The participants will have one disposable tourniquet applied to the left mid thigh by research personnel. The participants will then be randomized to the treatment group or sham group. The treatment group will receive 3 cycles of RIPC to the left lower leg by occluding blood flow at the thigh with a pneumatic cuff. Each cycle will consist of 5 minutes of ischemia by inflating the cuff to 300 mmHg followed by 5 minutes of reperfusion. The sham group will have the cuff inflated to no more than 15mmHg for three cycles as described above. Areas of hypersensitivity and allodynia will be obtained every 40 min for 280 min following the end of capsaicin application.

Detailed Description:

The purpose of this pilot study is to determine whether RIPC effects peripheral sensitization, central sensitization or both and determine effect size since there is no data regarding the presumed effect. These issues cannot be easily sorted out in patients experiencing postoperative pain and hypersensitivity, since surgery affects both components. In order to address this purpose the investigators will examine, in healthy volunteers, the effect of RIPC on a manipulation which generates hypersensitivity by an exclusive peripheral mechanism (ultraviolet B (UV-B) burn) and a manipulation which generates hypersensitivity by an exclusive central mechanism (topical capsaicin). Understanding the sites at which RIPC reduces the amplification of pain after injury will be useful in determining where it would be most logically applied clinically and in guiding preclinical mechanistic studies.

  Eligibility

Ages Eligible for Study:   18 Years to 55 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • healthy volunteers of both sexes ASA 1 or II classification
  • between the ages of 18-55
  • weighing less than 250 pounds
  • without chronic pain
  • not taking analgesics
  • off caffeine for 2 days.

Exclusion Criteria:

  • pregnancy
  • allergy to capsaicin
  • lower extremity vascular insufficiency
  • active treatment for DVT
  • severe thigh pain
  • taking psychotropic medications, including anti-depressants.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01541436

Contacts
Contact: Scott A Miller, MD 336-716-4498 scmiller@wfubmc.edu
Contact: Peggy Jordan, BS 336-716-7084 majordan@wfubmc.edu

Locations
United States, North Carolina
WakeForestUBMC Recruiting
Winston Salem, North Carolina, United States, 27157
Contact: Scott A Miller, MD    336-716-4498    scmiller@wfubmc.edu   
Principal Investigator: Scott A Miller, MD         
Sponsors and Collaborators
Wake Forest Baptist Health
Investigators
Principal Investigator: Scott A Miller, MD Wake Forest Baptist Health
  More Information

No publications provided

Responsible Party: Scott A Miller, Assistant Professor of Anesthesiology, Wake Forest University Baptist Medical Center
ClinicalTrials.gov Identifier: NCT01541436     History of Changes
Other Study ID Numbers: 00019284
Study First Received: February 3, 2012
Last Updated: May 28, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Wake Forest Baptist Health:
Remote Ischemic Preconditioning
Nociception
Central Sensitization
Peripheral Sensitization

Additional relevant MeSH terms:
Capsaicin
Antipruritics
Dermatologic Agents
Peripheral Nervous System Agents
Pharmacologic Actions
Physiological Effects of Drugs
Sensory System Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on October 20, 2014